Denki Kagaku Kogyo Kabushiki Kaisha

Hitachi, Ltd.

Takeshi Oda

Toru Arai

Shigeru Suzuki

Hiroyuki Kurimura

Norihiro Shimizu

Jun Watanabe

Toshiaki Otsu

Akio Okamoto

Masataka Nakajima

Yukiko Nishitoba

Takahiro Yamamoto

Takeshi Ootsuka

Hideki Toya

Shinobu Iriuchijima

Hirohiko Kobayashi

Masayuki Shinoyama

Takanori Naoe

Kyoji Aoki

Yoshifumi Nosaka

In recovery processing, a distributed storage systemlocks a storage area in which user data for recovery that is user data serving as data for recovery is stored in drives, and releases the lock after caching the user data for recovery in a memoryof any of computer nodes. Then, the distributed storage systemrecovers recovery target data on basis of the user data for recovery cached in the memory. In write processing, the distributed storage systemupdates the user data for recovery cached in the memoryin accordance with a write request and then writes the user data in accordance with the write request.

Computer system, control method, and recording medium

To provide a block copolymer composition excellent in balance of transparency, impact resistance, etc. in the form of not only an excluded product and a blow molded product but also an injection molded product. A linear block copolymer composition having at least three types of polymer blocks with different molecular weights each comprising a vinyl aromatic hydrocarbon as monomer units, wherein the molecular weight distribution of a mixture of the polymer blocks is within a specific range, and in GPC of the mixture, M/Mis within a specific range, where Mis the peak top molecular weight corresponding to a peak at which the peak top molecular weight becomes maximum among peaks forming a proportion of the area of at least 30% to the whole peak area, and M2 is the peak top molecular weight corresponding to a peak at which the peak top molecular weight becomes minimum among peaks at which the peak top molecular weight is at most 50,000 and which form a proportion of the area of at least 20% to the whole peak area.

Linear block copolymer composition

A block copolymer mixture containing a branched block copolymer characterized in that it has at least three types of polymer blocks with different molecular weights, each comprising a vinyl aromatic hydrocarbon as monomer units, the molecular weight distribution of a mixture of the polymer blocks S1, S2 and S3 each comprising a vinyl aromatic hydrocarbon as monomer units is within a specific range, and in a gel permeation chromatogram of the mixture of three types of the polymer blocks S1, S2 and S3, M1/M3 and M2/M3 are within specific ranges, where M1, M2 and M3 are peak top molecular weights of the respective polymer blocks.

Block copolymer mixture containing star-branched block copolymer

To provide a block copolymer composition having a good balance in transparency and impact resistance, and particularly having an excellent impact resistance, by making a molded product of injection molding under high sear condition in such a manner as to hardly generate anisotropy. A block copolymer composed of a hard segment block comprising a block made mainly of a vinyl aromatic hydrocarbon and a soft segment block comprising a block made mainly of a conjugated diene, characterized by having a remarkably improved impact resistance without degrading transparency in respect of not only an extrusion-molded product and a blow-molded product but also an injection-molded product, by blending two kinds of block copolymers having a hard segment block of a specific structure.

Block copolymer composition

A medical material and a medical device comprising an aromatic vinyl compound/&agr;-olefin random copolymer according to the present invention, are materials which contain substantially no chlorine and which have not only excellent flexibility, transparency and proper resilience but also radiation resistance and biocompatibility, and they are hence advantageously used especially in the medical field.

Medical Device

Ethylene/aromatic vinyl copolymer and molded product thereof

A resin composition characterized by comprising from 5 to 95 wt % of an aromatic vinyl compound/olefin random copolymer (A) which has an aromatic vinyl compound content of from 1 to 99 mol % and has a head-to-tail chain structure composed of two or more aromatic vinyl compound units, and from 95 to 5 wt % of an &agr;-olefin type polymer (B) and/or an aromatic vinyl compound type polymer (C) (provided that it is neither a medical material nor a medical device), which contains substantially no chlorine and is excellent in the impact resistance, moldability, weather resistance and chemical resistance and which is useful for an injection molded product, an extrusion molded product, a film, a sheet, etc. Further, it provides an excellent damping material.

Resin composition

A process for producing oxiracetam (4-hydroxy-2-oxo-1-pyrrolidineacetamide) useful as an agent for improving brain metabolism, under mild conditions and in a single process is provided, this process comprises reacting glycinamide with a butyric acid ester expressed by the formula ##STR1## wherein A represents a halogen atom or an epoxy group, B represents hydroxyl group, but when A is an epoxy group, A and B together form an epoxy group, and R represents an alkyl group.

Process for producing oxiracetam

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Tokyo, Japan

Takeshi Oda